Musk describes the hyperloop as something that is a "cross between a Concorde, a railgun and an air hockey table," and that it could go from San Francisco to New York City in 30 minutes.

Sounds like something straight out of a science fiction story right? Well, that's because it is. Even before Rand Corporation scientist R.M. Salter published a 17-page report detailing how something like the Hyperloop — or electromagnetically levitated and propelled cars in an evacuated tunnel — could be a reality in 1972, famed science fiction author Robert A. Heinlein wrote about "vacutubes" in his 1956 story "Double Star."

From "Double Star":

"We hit the sub-basement and went at once to the express tubes. A two passenger capsule was just emptying; Dak shoved me in so quickly that I did not see him set the door combination… The few minutes we had been crammed in the vacutube had been long enough for me to devise a plan…"

Other science fiction greats like Arthur C. Clarke and Larry Niven (1976's "A World out of Time," portrayed a gravity-assisted subway) also featured similar ideas on transportation.

And neither they nor Heinlein were the first. The earliest mention of travel by tubes in science fiction could be Michel Verne (son of Jules Verne) in the 1888 story, "An Express of the Future."

The story imagines riding air-driven carriages in submarine tubes from Boston to Liverpool, England in 2 hours and 40 minutes and reaching speeds of 1,800 kilometers per hour.

"Coming at once to the question of working, he filled the tubes--transformed into a sort of pea-shooter of interminable length--with a series of carriages, to be carried with their travelers by powerful currents of air, in the same way that dispatches are conveyed pneumatically round Paris."

As astounding as this is, science fiction ideas often have at the very least a starting point from which to build upon science fact. We can point to an 1812 document under the section "Calculations and Remarks Tending to Prove the Practicality, Effects and Advantages of a Plan for the Rapid Conveyance of Goods and Passengers Upon An Iron Road Through a Tube of 30 Feet in Area, of the Power and Velocity of Air" by George Medhurst where he introduces his idea of air-driven tube travel.

So there you go. The idea of traveling really, really ridiculously fast in tubes (at least in relation to the time period) across cities, entire continents or under oceans has been around for quite some time. Here's hoping Musk can take the concept from science fiction to science fact in our lifetimes.